Hardening of polymers containing carboxyl groups



United States Patent Ofitice 3,313,784 Patented Apr. 11, 1967 4 Claims.in. 26078.4)

This invention relates to a method for hardening carboxyl groupscontaining polymers and more particularly to a method for renderingthese polymers insoluble in water.

It is known to harden carboXyl groups containing polymers by heatingthem in the presence of compounds having in their molecule at least oneprimary or secondary amino group (German patent specification 864,151).

A process has now been found for rendering carboxyl groups containingpolymers insoluble in water by reacting these polymers with compoundsbearing two active halogen atoms and corresponding to the formula:

wherein:

each of X and X (the same or different) represents a halogen atom e.g. achlorine atom or a bromine atom,

each of R R R and R, (the same or two or more of them different)represents a hydrogen atom or an alkyl group, and

A represents an arylene radical,-

wherein R represents a hydrogen atom or an allryl group.

In addition to homopolymers and copolymers prepared from acrylic acid,methacrylic acid, fumaric acid, maleic acid, itaconic acid, citraconicacid and the like, the semi-esters of polyvinyl alcohol and dicarboxylicacids such as phthalic acids, maleic acid, succinic acid etc. can alsobe used as carboxyl groups containing polymers. Moreover, naturalproducts or their carboxyl groups containing substitution products canbe hardened to waterinsoluble products according to the process of thisinvention. Examples of these latter products are: alginic acid, pectine,the monoesters of dicarboxylic acids and cellulose, starch, amylopectineand the semi-esters and semiethers thereof, or carboxyalkyl andcarboxyaryl derivatives of these natural polymers such as carboxymethylcellulose.

All these carboxyl groups containing polymers can be hardened accordingto the process of the invention by reacting them with compounds bearingat least two active halogen atoms and corresponding to the aboveformula.

Among the compounds which have the above general formula we particularlyrefer to the following:

Methylene-bis-chloroacetamide ClCl-l CO-NHCH -NHCOCH Cl which can beprepared according to Ann. 343, 284 (1905);

Bis(chloroacetyl)-amine ClCH CONHC0CH Cl which can be prepared accordingto J. Prakt. Chem. [2] 69, 11 (1964);

N ,N-bis chloroacetyl -ethylenediamine ClCH CONHCH -CH NH-CO--CH Clwhich can be prepared according to J. Chem. Soc. (1947), 129;

p-Xylene dibromide which can be prepared according to Ann. 155, 340(1870);

N,N-bis (chloroacetyl) -hydrazine ClCH -CO-NH-NHCOCH -Cl which can beprepared according to German patent specification 819,405;

N,N'-bis(chloroacetyl)-urea Cl-CH CONHCO-NH-COCH C1 which can beprepared according to Receuil Trav. Chim.

des Pays-Bas, 31, 119 (1912);

N,N'-bis a-bromopropionyl) -ethylenediamine H CCHBr-CON HCH CHNH-COCHBrCH which can be prepared according to Z. Physiolog. Chem. 123,280 (1922);

1,2-bis (monobromoacetoxy) -ethane BrCH COOC-H -CH OCOCH Br which can beprepared by reacting monobromoacetic acid with ethylene dioxide;

N,N-dibromoacetylethylenediamine BrH C-CO-NH-CH -CH NHCO-CH BrN,N'-dibromoacetylpropylenediamine-1,3 B1*H CCOI IH-CH CH CH -NHCOCH BrN,N-bis (bromoacetyl -hydrazine BrH CCONH-NHCO-CH Br N,N'-bis(chloroacetyl) -dirnethylhydrazine ClHnCOONN-C O-OHrOl H3O OH: N,N-bis(bromoacetyl -dimethy1hydrazine N,N'-dibromoacetylethylene diamine canbe prepared as follows:

To a solution of g. (0.5 mol) of bromoacetyl bromide in 500 cm. ofchloroform is added dropwise over a few hours and whilst cooling asolution of 37 g. of ethylene diamine (0.6 mol) in 100 cm. ofchloroform. The suspension is still stirred for a few hours at 510 C. Awhite precipitate is obtained which is Washed with water andrecrystallized from dioxane. Melting point: C.

Analysis.Br, percent calculated: 53; found: 53.05. N, percentcalculated: 9.27; found: 9.31, 9.35.

N,N'-dibromoacetylpropylenediamine-1,3 can be prepared as follows:

100 g. (0.5 mol) of bromoacetylbromide is dissolved in 500 cm. ofchloroform. Over a few hours is dropwise added whilst cooling a solutionof 44.5 g. of trimethylenediamine (0.6 mol) in 100 cm. of chloroform.The formed suspension is stirred for a few hours at 5 C. and theobtained white precipitate is sucked off and thoroughly washed withWater. The residue is recrystallized from water. Melting point: 106 C.

Analysis.Br, percent calculated: 50.6; found: 51. N, percent calculated:8.86; found: 8.86, 8.68. C, percent calculated: 26.6; found: 26.63. H,percent calculated: 3.8; found: 3.89.

N,N-bis(bromoacetyl)-hydrazine is prepared as follows:

52 g. of bromoacetic anhydride are dissolved in dioxane. 7.6 g. ofhydrazinecarboxylic acid are then added at 40 C. whilst stirring andcarbon dioxide escapes. The reaction mixture is then stirred for /2 hourat the same temperature. A precipitate is formed which is sucked off andrecrystallized from a mixture of alcohol and water. Yield: 43%. Meltingpoint: 205 C.

N,N-bis(chloroacetyl)-dimethylhydrazine is prepared as follows:

106 g. of sodium carbonate and 45 g. of dimethyb hydrazine hydrochlorideare dissolved in 750 cm. of water. Then 100 g. of chloroacetylchlorideare dropwise added at 25 C. A white precipitate is formed. After coolingand sucking off, the product obtained is recrystallized from water.Yield: g. Melting point: 120 C.

Analysis.-N, percent calculated: 13.15; found: 13.53, 13.33. Cl, percentcalculated: 33.29;found: 33.66, 33.97.

N,N'-bis(bromoacetyl)-dimethylhydrazine is prepared as follows:

21.2 g. of sodium carbonate and 9 g. of dimethylhydrazine are dissolvedin 150 cm. of water. Next 28 g. of bromoacetyl chloride are dropwiseadded at C. A white precipitate is formed. After cooling, thisprecipitate is sucked off and recrystallized from water. Yield: 7.5 g.Melting point: 96 C.

Analysis.N, percent calculated: 9.4; found: 10. Br, percent calculated:53.7; found: 54.4.

According to an embodiment of the invention, the carboxyl groupscontaining polymer together with the compound bearing active halogenatoms are coated onto a support from a common solution in water, in anorganic solvent or in a mixture of both, whereupon the solvent isevaporated by heat or removed by any other method. In this way a film ora covering layer of the polymer is obtained. Already after a very shorttime the polymer is cross-linked by means of the compound bearing activehalogen atoms, whereby the film or layer which is formed from thepolymer becomes insoluble.

The compounds bearing active halogen atoms can also be taken up by thecarboxyl groups containing polymers in another Way. In this way shapedarticles such as films, layers, threads etc. which are prepared from thecarboxyl groups containing polymer can be immersed in a solution of thecompound bearing active halogen atoms. Of course, in this case a solventhas to be used wherein the polymer itself is insoluble or which is atmost a swelling agent for the carboxyl groups containing polymer. Thesolvent is at least superficially taken up by the polymer whereby theactive halogen atoms can react with the carboxyl group of the polymer,this giving rise, at least superficially, to cross-linking andinsolubilization of the polymer.

The carboxyl groups containing polymers which are hardened according tothe process of this invention are insoluble in water, they areconsiderably more thermostable and generally their swelling power inorganic solvents is also decreased. The number of cross-links whicharise by the reaction of the halogen atoms with the carboxyl groups aredetermined by the number of carboxyl groups which are present in thepolymer and by their ratio to the number of compounds bearing activehalogen atoms.

The polymers which are hardened in this way possess more possibilitiesfor application in the industry. S0 alginic acid is very much used as asizing agent in the textile industry and if it is treated according tothe process of the present invention, it resists to the action of allkinds of detergents.

According to the invention a large series of Waterinsoluble polymers canbe obtained, which were soluble in a preceding step and thus can easilybe worked up. So, covering layers can be coated onto wood, textile,paper, fibres, metals etc. from aqueous solutions of these carboxylgroups containing polymers which contain the hardening agents accordingto the invention, whereby the formed layers become water-insoluble afterdrying.

These carboxyl groups containing polymers are used on a very large scalein the photographic industry. Up to now the carboxyl groups containingpolymers have been used for the manufacture of all kinds of layers suchas: layers of which the binding agent of the light-sensitive silverhalide and other salts wholly or partly consists of these polymers,subbing layers, antistatic layers, filter layers, anti-stress layers,all kinds of interlayers etc. This enumeration relates to materials usedin the common black-White photography, the colour photography or thephotomechanical reproduction technique as Well as to materials used inX-ray photography, elect-rophotography and reproduction techniques bymeans of silver complex diffusion transfer.

The following examples illustrate the invention.

Example 1 To 100 cm. of a 5% neutralized aqueous solution of thesemi-ester of maleic acid and polyvinyl alcohol prepared according tothe method of the British patent specification 822,061 and containing16% of vinyl maleate groups, 5 cm. of a 5% solution ofN,N'-bis(bromoacetyl)-ethy1ene diamine in dimethylformamide are added.

The solution is brought at pH 7, coated onto glassplates and dried atroom temperature. Already after some days of storage the obtained layersresist a treatment in boiling water whereas a layer containing noN,N'-bis d (bromoacetyD-ethylene diamine even dissolves in cold water.

Example 2 To 100 cm. of a 5% aqueous solution of sodium alginate, 1 cm.of a 5% solution of N,N'-bis(bromoacetyl)-ethylene diamine in dimethylformamide is added. The solution is brought at pH 7, coated ontoglass-plates and dried at room temperature. Already after some days ofstorage the obtained layers resist a treatment in boiling water.

Example 3 To 100 cm. of a 5% neutralized aqueous solution of thesemi-ester of o-phthalic acid and polyvinyl alcohol containing 20% ofo-phthalyl groups, 5 cm. of a 5% solution ofN,N'-bis(bromoacetyl)-ethylene diamine in dimethyl formamide are added.

The solution is brought at pH 8, coated onto glassplates and dried atroom temperature. Already after some days of storage the obtained layersresist a treatment in boiling water.

Example 4 (a) To 100 cm. of a 5% aqueous solution of a copoly[styrene/acrylic acid] containing 36.4% by weight of acrylic acid, 10cm. of a 5% solution of N,N'-bis (bromoacetyl)-ethylene diamine indimethyl formamide are added. The solution is brought at pH 7, coatedonto glass-plates and dried at room temperature. After 36 hours ofstorage at 55 C. and 37% relative humidity such layers resist to atreatment in water at C. They resist much better mechanical damage thanlayers which are coated from a solution containing no hardening agent.

(b) When the above copolystyrene/acrylic acid is replaced bycopolystyrene/methacrylic acid containing 65.8% by weight of methacrylicacid an analogous hardening is reached.

Example 5 To 100 cm. of a aqueous solution of cellulose acetomaleatewith a substitution degree of 2.2 of acetyl groups and 0.45 ofmonomaleyl groups, 5 cm. of a 10% solution ofN,N-bis(bromoacetyl)-ethylene diamine in dimethyl formamide are added.The solution is brought at pH 7, coated onto glass-plates and dried atroom temperature.

After 36 hours of storage at 55 C. and 37% relative humidity such layersresist a treatment in boiling water without dissolving.

Example 6 To 100 cm. of a 10% neutralized aqueous solution of thesemi-ester of maleic acid and polyvinyl alcohol which is preparedaccording to the method of the British patent specification 822,061 andwhich contains 14% of vinyl maleate groups, cm. of a 5% solution of1,2-bis (monobromoacetoxy)-ethane in ethanol are added. The solution isbrought at pH 7, coated onto glass-plates and dried. After 36 hours ofstorage at 55 C. and 37% relative humidity such layers resist atreatment in water of 80 C. without dissolving.

Example 7 To 100 cm. of a 10% aqueous solution of the semiester ofmaleic acid and polyvinyl alcohol, prepared as described in the Britishpatent specification 822,061 and containing 16% of maleate groups, 20cm. of a 5% solution of p-Xylene dibromide in dimethyl formamide areadded. This solution is brought at pH 7, coated onto glass-plates anddried at room temperature. After 36 hours of storage at 55 C. and 37%relative humidity such layers resist a treatment in water of 90 C.without dissolving.

Example 8 1 kg. of a highly sensitive photographic silver halideemulsion containing as a binding agent the sodium salt of the semi-esterof maleic acid and polyvinyl alcohol, prepared according to the Britishpatent specification 822,061 and containing 16% of vinyl maleate groupsis prepared. To this emulsion 30 cm. of a 10% solution of N,N'-bis(brornoacetyl)-ethylenediarnine in dimethyl formamide are added. Theemulsion is coated onto a support and dried.

Already after a very short period of storage, the obtained emulsionlayer resists mechanical damage during processing very well, whereas anemulsion layer containing no poly(vinyl monornaleate) already dissolvesin cold water.

Example 9 To 100 cm. of a 5% aqueous solution of a copoly[styrene/maleic acid], 2 cm. of a 5% solution of N,N'-bis(bromoacetyl)-ethylenediamine are added. This solution is coated ontoglass-plates and dried.

Already after some days of storage such layers are insoluble in boilingwater. A layer coated from the solution of the copolymer to which nohardening agent has been added already dissolves in cold water.

Example 10 To 100 cm. of a 5% aqueous solution at pH 7 of ethylcellulose succinate with a substitution degree of 2.2 of ethyl groupsand 0.5 of succinyl groups, 1 cm. of a 5% solution ofN,N'-bis(bromoacetyl)ethylene diamine in dimethylformamide is added. Thesolution is coated onto glass-plates and dried.

Already after some days of storage at room temperature the thus formedlayers do not dissolve anymore, even in boiling water. Layers which havebeen coated from a solution of ethyl cellulose succinate to which nohardening agent has been added, already completely dissolved at 30 C.

Example 11 Example 10 is repeated but the amount of ethyl cellulosesuccinate is replaced by a same amount of amylopectine-o-phthalate witha substitution degree of 0.35 of o-phthalyl groups. Already after somedays of storage, the formed layers do not dissolve anymore, even inboiling water.

Example 12 Example 10 is repeated but the amount of ethyl cellulosesuccinate is replaced by a same amount of ethyl cellulose maleate with asubstitution degree of 2.25 of ethyl groups and 0.5 of maleate groups.Instead of 1 cm. of a 5% solution of N,N'-bis(bromoacetyl)ethylenediamine in dimethyl formamide, 5 cm. of the same solution are added.Already after some days of storage at room-temperature the formed layersdo not dissolve anymore, even in boiling water.

Example 13 To a 5% aqueous solution of ethyl cellulose-ophthalate with asubstitution degree of 2.25 of ethyl groups and 0.35 of o-phthalylgroups, 1 cm. of a 5% solution of N,N'-bis(bromoacetyl)-ethylene diaminein dimethyl formamide is added. The solution is coated onto glass-platesand dried. After some days of storage at room temperature the formedlayers resist processing in boiling water.

We claim:

1. The method of hardening a polymer containing carboxyl groups, whichmethod comprises contacting said polymer with a compound having theformula wherein:

each of X and X represents a halogen atom selected from the groupconsisting of chlorine and bromine, each of R R R and R represents amember selected from the group consisting of a hydrogen atom and analkyl group, and A represents a member selected from the groupconsisting of an arylene group, a COO-alkylene-OCO group, aCO-O-arylene-OCO group, a CONH-CONHCO- group, a -CO--NHCOCONHCO group, a-CONHCO-alkylene-CO--NHCO 2. The method of rendering water-insolublenormally water-soluble polymers containing carboxyl groups, which methodcomprises contacting said polymer with a compound having the formulawherein:

each of X and X represents a halogen atom selected from the groupconsisting of chlorine and bromine, each of R R R and R represents amember selected from the group consisting of a hydrogen atom and analkyl group, and A represents a member selected from the groupconsisting of an arylene group, a CO-O-alkylene-O--CO group, a--COO-arylene-OCO- group, a CONH-CO-NH-CO- group, a CO-NH-COCONHCOgroup, a CONHCO-alky1ene-CONHCO- p, a -CO--NH-CO-arylene-CO-NH-CO-group, a CONHSO -alkylene-SO NH-CO-- p, a -CO-NHCO group, aCON(alky1)-CO group, a CO-NHNHCO group, a CON(alkyl)-NHCO- group, a-CO-N(alkyl)-N(alkyl)-CO group,

group.

3. The method of claim 1 wherein said polymers and said compound arecontacted by the steps comprising mixing said compound with a solutionof said polymer and thereafter evaporating the solvent.

4. A shaped article prepared by the method of claim 1.

References Cited by the Examiner UNITED STATES PATENTS 3,002,837 10/1961Burgardt et al. 96--84 FOREIGN PATENTS 860,632 2/1961 Great Britain.880,485 6/1953 Germany.

NORMAN G. TORCHIN, Examiner.

A. LIBERMAN, L. G. CHILDERS, Assistant Examiners.

1. THE METHOD OF HARDENING A POLYMER CONTAINING CARBOXYL GROUPS, WHICHMETHOD COMPRISES CONTACTING SAID POLYMER WITH A COMPOUND HAVING THEFORMULA